What is the WinSxS folder, and can I delete it?

WinSxS is the Windows component store. It looks huge but much of it is shared with C:\Windows. Here is how to shrink it safely without deleting it.

C:\Windows\WinSxS is the Windows component store. It holds the files Windows needs to install features, apply updates and repair itself.

Why it looks so big

Many files in WinSxS are hard links: the same file appears both in WinSxS and in C:\Windows\System32, but it is stored on the disk only once. File Explorer counts it twice, so WinSxS often looks much bigger than the space it really uses.

Can I delete it?

No. Deleting WinSxS or files inside it by hand can stop Windows from updating, installing features or even starting. Never change its permissions to delete it.

How to shrink it safely

• Open Command Prompt as administrator and run Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore to see its real size and whether cleanup is recommended.
• Run Dism.exe /Online /Cleanup-Image /StartComponentCleanup to remove superseded versions of updated components.
• Or use Disk Cleanup › Clean up system files › Windows Update Cleanup.

Windows also runs this cleanup automatically as a scheduled task.

See what really fills your drive

WinSxS is rarely the real reason a drive is full. Scan with PCMap to see which folders and files are actually large. Read more: why drive C: fills up.